title: Overexpression of Bmi-1 in uterine cervical cancer: correlation with clinicopathology and prognosis.
abstract: B-cell-specific Moloney murine leukemia virus integration site 1 (Bmi-1) is a member of polycomb group, which participates in axial patterning, hematopoiesis, cell cycle regulation, and senescence. Recently, overexpression of Bmi-1 has been reported in various human cancers and proved to be associated with poor survival. The aim of this study was to investigate the expression of Bmi-1 protein in human uterine cervical cancer (UCC) and explore its associations with clinicopathological factors and prognosis.
  
  
  
  Western blot was used to detect the expression of Bmi-1 in 4 human cervical cancer cell lines (Hela, SiHa, CasKi, and C33A) and a normal cervical epithelial cell line. In addition, 152 UCC and 30 adjacent normal cervical paraffin-embedded samples were collected to detect Bmi-1 expression by immunohistochemistry.
  
  
  
  Western blot analysis showed Bmi-1 was overexpressed in 4 human UCC cell lines but not in the normal cervical epithelial cell line. Moreover, immunohistochemical staining revealed Bmi-1 was overexpressed in 63.2% UCC tissues (Bmi-1 ++ or +++), and the overexpression of Bmi-1 protein was significantly correlated with tumor size (P = 0.046), clinical stage (P = 0.021), and regional lymph nodes metastasis (P = 0.010). Survival analysis showed a significant difference between Bmi-1 protein overexpression and poor survival (P = 0.021). Cox proportional hazards risk analysis indicated that Bmi-1 protein overexpression was an independent prognostic factor for overall survival.
  
  
  
  B-cell-specific Moloney murine leukemia virus integration site 1 is overexpressed in UCC and correlated with adverse clinical characteristics and poor prognosis, which suggests that the Bmi-1 might participate in the development and progression of UCC and have clinical potential not only as a useful predictor of aggressive phenotype but also a promising prognostic predictor.
authors.affiliation: Department of Clinical Laboratory, Qilu Hospital, Shandong University, Jinan, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.forename: Chuan-Xin
authors.initials: CX
authors.lastname: Wang
authors.forename: Cheng-bao
authors.initials: CB
authors.lastname: Zhu
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.forename: Shi-feng
authors.initials: SF
authors.lastname: Kan
authors.forename: Lu-tao
authors.initials: LT
authors.lastname: Du
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Li-li
authors.initials: LL
authors.lastname: Wang
authors.forename: Shun
authors.initials: S
authors.lastname: Wang
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000235:genetics / Q000473:pathology; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000235:genetics; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000235:genetics* / Q000473:pathology; D045744:Cell Line, Tumor; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006367:HeLa Cells; D006801:Humans; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009687:Nuclear Proteins / Q000235:genetics*; D063150:Polycomb Repressive Complex 1; D011379:Prognosis; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D012097:Repressor Proteins / Q000235:genetics*; D015854:Up-Regulation; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis* / Q000235:genetics* / Q000473:pathology; D055815:Young Adult
chemical_list: C069077:BMI1 protein, human; D014408:Biomarkers, Tumor; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D012097:Repressor Proteins; D063150:Polycomb Repressive Complex 1